Even with heads flow on the dyno it show engines at least under 7000 rpm aren't as sensitive as people generally make them out to be, maybe on the street and or track might be a different story, but with over a hundred years of automotive racing if small was generally better 200-599 cfms we would of found that out to be true by now. And that the average person doesn't generally run anything smaller than a 600 cfm carb even on small stock/mild V8's. And 600 cfm by that formula roughly equals about 450 hp so if your making less than 450 hp and running a 600 cfm carb or larger apparently your over doing it.